This invention relates to certain compounds and processes for their manufacture. More specifically, it relates to compositions and processes useful in the manufacture of lubricating oil additives, especially dispersants and detergents.
Present-day automobile and diesel engines have been designed for higher power output, lower combustion products emission and longer in-service periods of use of crankcase lubricating oils. These design changes have resulted in such severe operating conditions as to necessitate devising higher efficiency lubricating oils that will, under the increased severity of in-service use, afford proper protection against corrosion and the accumulation or deposition of sludge, varnish and resinous materials on the surface of engine parts which rapidly accelerate decrease in both operating efficiency and life of the engine. The principal ingredient of crankcase lubricants is a base lubricating oil, a mixture of hydrocarbons usually derived from petroleum. Even when highly refined by removal of deleterious components, such as polymerizable components, acid formers, waxes, etc., a lubricant base oil still requires the addition of a number of oil-soluble chemical additives to enable the oil to resist oxidation, deposition of sludge and varnish on, and corrosion of, the lubricated metal parts, and to provide added lubricity and regulated viscosity change from low to high temperature. These ingredients are commonly known as anti-oxidants, dispersant-detergents, pour point dispersants, etc.
Combustion products from the burning of fuel and thermal degradation of lubricating oils and addition agents tend to concentrate in the crankcase oil with the attendant formation of oil-insoluble deposit-forming products, that either surface coat the engine parts with varnish or lacquer-like films or settle out on the engine parts as viscous sludge deposits or form solid ash-like or carbonaceous deposits. Any of such deposits can restrict, and even plug, grooves, channels and holes provided for lubricant flow to the moving surfaces of the engine requiring lubrication, thus accelerating the wear and reducing the efficiency of the engine. In addition, acidic combustion products corrode the lubricated metal surfaces. Chemical additives are blended in crankcase oil formulations not only to reduce thermal decomposition of the oil and addition agents (anti-oxidants) but also to keep in suspension (as a dispersant) and to resuspend (as a detergent) insoluble combustion and degradation products as well as to neutralize acidic products (anti-corrosion agents). A separate additive is commonly added for each improvement to be effected.
Numerous detergents or dispersants for lubricating oils have been developed, some of which are based on a substituted phenol as an intermediate. For example, substituted phenols can be reacted with formaldehyde and an amine having a reactive nitrogen in a Mannich condensation reaction, thereby affording an oil soluble lubricating oil additive. Commonly used substituted phenols are alkyl substituted, especially polymer substituted phenols.
Polymer-substituted phenols having the formula: ##STR2## are well known in the art. Typically, R is derived from polypropylene or polybutene having an average number of carbon atoms ranging from about 50 to about 20,000. The polymer-substituted phenol can be prepared by alkylating phenol with the polymer in the presence of BF.sub.3 catalyst. This procedure and products formed thereby are disclosed in British Pat. No. 1,159,368. BF.sub.3 is generally the catalyst of choice for the alkylation reaction. Other Friedel-Crafts catalysts such as AlCl.sub.3 are generally unsatisfactory because their use results in extensive degradation of the polymer. Even with the use of BF.sub.3 the alkylation must be carried out under carefully controlled reaction conditions to minimize polymer degradation. Because of the susceptibility to degradation of the polymer substituent, attempts to further alkylate polymer-substituted phenols under Friedel-Crafts conditions have generally been unsuccessful. It is often desirable to further substitute the alkyl phenol to improve oil solubility and possibly improve the effectiveness of reaction products made therefrom.
It is an object of this invention to provide a process for the alkylation of alkyl phenol which does not substantially degrade the alkyl group.
It is an object of this invention to provide a multi-substituted phenol which is useful in the manufacture of lubricating oil additives.
It is further an object of this invention to provide intermediates for the manufacture of highly effective lubricating oil detergents or dispersants.